models : fix YaRN regression + consolidate logic (#18006)

* models : fix YaRN regression + consolidate logic

* cont : fix the fix

* cont : remove header

* cont : add header

src/llama-hparams.cpp

@@ -3,7 +3,6 @@
 #include "ggml.h"
 
 #include <cassert>
-#include <cmath>
 
 void llama_hparams::set_swa_pattern(uint32_t n_pattern, bool dense_first) {
     if (dense_first) {
@@ -231,13 +230,3 @@ bool llama_hparams::is_masked_swa(uint32_t n_swa, llama_swa_type swa_type, llama
 
     return false;
 }
-
-float llama_hparams::yarn_attn_factor_adjust(float attn_factor, float freq_scale, float ext_factor) {
-    GGML_ASSERT(ext_factor >= 0.0f);
-
-    if (ext_factor != 0.0f) {
-        attn_factor *= 1.0f / (1.0f + 0.1f * logf(1.0f / freq_scale));
-    }
-
-    return attn_factor;
-}